A circular brush cutting blade is typically a planar disk having its circumference provided with cutting teeth. It is mounted at the end of a long handle with a drive shaft producing rotation of the blade about its axis. Cutting of grass, brush and the like (hereafter collectively referred to as foliage) is achieved with a sweeping motion, e.g., with the blade moved parallel to the ground to cut the brush and grass, etc. close to the ground but spaced above the ground.
Occasionally there is a need to cut into or adjacent the ground, e.g., for total removal of a weed or unwanted plant, and in order to do so with the above conventional brush cutting blade, the blade has to be angled wich is difficult to control and generally unsatisfactory.
A modified brush cutting blade is disclosed in U.S. Pat. No. 5,361,570. The blade provides multiple blade segments at a position inward of the blade's periphery which are formed by being partially severed from the blade body and bent downwardly at right angles from the plane of the blade. A leading edge of the segments is provided with teeth for cutting foliage, e.g., in a digging or mostly up and down motion of the blade but combining both sweeping and vertical motions.
There are two major problems with the blade of the '570 patent. The bent segments provide vertical faces (both inner and outer faces) which tend to push the foliage rather than cut it (in a sweeping motion). Secondly, the segments provide a catch basin, i.e., the material that is cut will be thrown against the flat inner face of the blade segments and cling to the blade. This can cause undesired vibration and interference with the cutting action.